Choose the correct number of nonbonding electrons in the Lewis structure for CN^- ion.

Question

Quizplus · Accepted Answer

To determine the number of nonbonding electrons in a Lewis structure, we need to calculate the total number of valence electrons for the ion and subtract the electrons involved in bonding. CN^- ion: C - 4 N - 5 S - 6 U - 7 P - 5 Adding all up, we get a total of 27 valence electrons. First, we need to determine the central atom. In this case, it is sulfur (S). Then, we can draw a skeleton structure where all atoms are connected by single bonds. :S-C-N-Si-P: The total number of electrons used in bonding is 2(4) + 2(1) + 2(1) + 2(0) + 2(5) = 22 (two electrons are used for each bond). The remaining valence electrons are 27 - 22 = 5. These 5 electrons are then placed around the atoms to satisfy the octet rule. Sulfur and phosphorus can accommodate more than 8 electrons as they are in the third period, so we can place the remaining electrons on them. To do this, we add lone pairs around sulfur and phosphorus until they have 12 electrons each. :S=C=N=S=Si=P:: Now we can count the nonbonding electrons, which are the lone pairs around the atoms. There are 4 lone pairs around sulfur and none around phosphorus for a total of 4 nonbonding electrons.

Choose the Correct Number of Nonbonding Electrons in the Lewis